Solution to

Frame 2-20.

Suppose you had two fractions, one with a denominator of "3" and the

other with a denominator of "4." One method of getting a common

denominator

denominator is to multiply the denominators together. For a problem

with two denominators ("3" and "4"), a common denominator would be

denominator

"12" (3 x 4 = 12 and 4 x 3 = 12).

Finish solving the following problem:

1

1

1

4

1

3

4

?=

?

+

=

X

+

X

=

+

3

4

3

4

4

3

12

12

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Solution to

Frame 2-21.

Solve this subtraction problem:

4

5 _ 3

=

+

=

6

8

12

12

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Solution to

Frame 2-22.

Although multiplying the denominators together will always give you a

common denominator, sometimes a smaller common denominator can

be found. Consider the previous problem? Can you think of a common

5x8 _ 3x6

40-18=

=

=

denominator for 5/6 and 3/8 that is smaller than 48? What number will

6x8 8x6

48

both 6 and 8 divide into and the quotients be whole numbers (no

remainders)?

22

____________

48

Work the problem 5/6 3/8 again using the smaller common

denominator. (Divide the denominator into the common denominator and

multiply the numerator by the quotient.)

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Solution to

Frame 2-23.

You can add and subtract fractions in the same problem. Just make

sure that each denominator divides evenly into the common denominator.

24

Try this problem.

5x4 _ 3x3

20-9= 11

1 _ 1

1 _ 1 + 1 _ 1

=

=

+

6x4 8x3

24 24

2

3

5

7

9

11

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MD0900

2-9

Integrated Publishing, Inc. |